This is a revised competing renewal application for an environmental toxicology training program for 6 pre-doctoral and 3 postdoctoral fellows. Since this program started in 1990, training has been provided to 9 postdoctoral fellows and 29 pre-doctoral fellows. The 14 trainees who have completed their formal education have professional positions where they are utilizing their toxicology knowledge for basic research, biotechnology, or practical problems of environmental risk assessment. Three have academic faculty positions. Long-term goals of those who are pursuing further training in fellowships (6) or in law school (3) are also to address health problems of environmental agents. 100% of the 9 who sought an individual postdoctoral fellowship were successful, including 5 F32 awards from the NIEHS, which the investigators consider a positive reflection of their requirement that every trainee submit a competitive research proposal. The investigators propose research training in three areas where they have a critical mass of experienced faculty and superb physical resources for state of the art research. These three areas of pathophysiology, DNA damage and repair, and biotransformation and transport share a unifying theme of oxidant injury. Training in the broad area of pathophysiology will focus on toxic agent injury to the GI tract, CNS (i.e., brain and ocular tissue), and lung; this latter site meshes with new participation by clinician-scientist faculty in their recently approved Asthma and Allergic Disease Center. An additional, unique feature of the proposed training is that the research by several faculty in each area includes assessments of the influences of aging and infection. A totally updated curriculum builds upon the reorganization of the graduate school towards an interdisciplinary common first year curriculum. Core courses in mechanistic and advanced toxicology culminate in student preparation and peer review of research proposals. Novel aspects of the toxicology program curriculum for pre- and postdoctoral fellows: are 1) a distance education toxicology course that is conducted by trainees with faculty supervision, and 2) mini-courses on specialized topics that is taught by visiting experts. Hallmarks of institutional commitment include full funding of stipends for the first 4 terms of graduate school and remarkable support for new and bridging faculty grants from endowments. Key elements in the investigators? outstanding climate for training are a multiplicity of environmental-health relevant research centers supported by the NIEHS and a local foundation, notably a new (March 2000) Sealy Center in Environmental Health and Medicine.